The preparation of thermo-responsive palladium catalyst with high activity for electroless nickel deposition

In this study, a temperature-responsive palladium catalyst for electroless nickel deposition was prepared. The noble metal nanoparticles that was reduced and stabilized by styrene-N-isopropylacrylamide oligomer (St-co-NIPAAm) showed good dispersion and excellent stability in the aqueous solution without surfactant and reductant in the mixture. The catalytic activity of St-co-NIPAAm/Pd is much higher than that of conventional Sn/Pd colloids. It was found from our result that a nickel film with dramatically enhanced adhesion is formed on the PET surface without special pretreatment step, indicating that St-co-NIPAAm was used not only as the adsorption sites for palladium, but also as an adhesion-promoting layer for the electrolessly deposited nickel on the PET surface. The properties of St-co-NIPAAm/Pd nanocomposite and deposition rate of electroless nickel deposition (EN) were characterized by transmission electron microscopy (TEM), quartz crystal microbalance (QCM), Fourier transform infrared spectrometry (FT-IR), gel permeation chromatography (GPC) and UV–Vis spectra.